BACKGROUND
Ring chromosome 20 syndrome is a rare chromosomal disorder.
METHODS
In six patients, we focused on the presenting epileptic phenotype, the behavioral and mental problems and the relationship between the ratio of mosaicism and the age at onset of the epilepsy.
RESULTS
All patients presented with pharmacoresistant frontal lobe complex partial… (More)

Mutations in the methyl-CpG-binding protein 2 (MECP2) gene located on Xq28, cause Rett syndrome (RTT) in female patients. Meanwhile, nonmosaic MECP2 mutations unknown in girls have been found in an increasing number of male patients with a normal 46, XY karyotype. They can cause a broad spectrum of neurodevelopmental disorders which often show a combination… (More)

OBJECTIVE
To study the occurrence of congenital aural atresia in patients with a deletion of the long arm of chromosome 18 (18q- deletion or de Grouchy syndrome).
STUDY DESIGN AND PATIENTS
This retrospective study presents an overview of the otologic findings in 33 Dutch and Belgian patients with a deletion of 18q.
MATERIALS AND METHODS
Detailed… (More)